GB741803A - Improvements in and relating to the manufacture of master models for use in the production of industrial models, such as automobile bodies - Google Patents

Abstract

741,803. Surface gauges. KISH PLASTIC PRODUCTS, Inc. Dec. 18, 1950, No. 30788/50. Class 106 (2). [Also in Groups V, XXII and XXIII] A method of making a master model of an automobile &c. having bilaterally symmetrical parts consists in preparing a preliminary model, shaping one symmetrical part to finished form and then finishing the other part by using templates made from the first part. A plaster cast 142 with built-up ribs is first taken of, say, the bonnet panel, of an automobile clay &c. master model bearing skin panel joint lines. The cast is turned over and a male plaster cast taken, the plaster being retained by walls 148. This cast 146 is trimmed to the joint lines 135 as at 150, Fig. 6, and can be used for roughing-out jigs &c. The mould 142, 148 is then used again to make a plastic cast such as a resinous plastic with a polystyrene core. The plastic model 154 is trimmed to remove irregularities reproduced from the clay model. Use is made of templates prepared from body drafts to ensure the correct panel outline. One half of the model is then shaped by cutting away and adding plastic material until a smooth surface is obtained. Scribe marks 166, Fig. 8, are made on the surface and plastic-faced templates made so that the other half can be exactly duplicated. The templates are mounted, for the latter purpose, on a framework 172, 174, Fig. 10, and surplus material is trimmed by a routing or planing cutter. If material is to be added, the surfaces are first built-up under the template and the intervening space is then-smoothed in. Finally a female reproduction is made using a strengthening frame 152, Fig. 14, and a plastic facing 184. The male and female models are used for making tools and fixtures or further models.